The angular dislocation parallel to a free surface. Application to a (111)Si low angle twist boundary

Salem Neily (1) , Sami Youssef (2) , Frank Fournel (3) , R. Bonnet (4)

1 FSM - Faculté des Sciences de Monastir
2 Unité de Recherche de Physique des Solides [Monastir]
3 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
4 SIMaP - Science et Ingénierie des Matériaux et Procédés

The elastic displacement field of a sharply angular dislocation with its two legs parallel to a planar free surface is given in a practical analytical form. Its expression gives access, in transmission electron microscopy (TEM), to computed images of numerous interacting dislocations all located at a distance h close to the free surface. As an application, this field is used repeatedly to study, in dark-field TEM and a g(3g) diffraction mode with g{220}, the contrast of dissociated triple nodes of a low-angle twist boundary in silicon extended over a (111) plane. It is shown that free surface elastic effects can influence the contrasts of some 30° partials if h is at nanometer scale.

Mots clés: Physical Sciences

Domaines: Matière Condensée [cond-mat]; Matériaux

Salem Neily, Sami Youssef, Frank Fournel, R. Bonnet. The angular dislocation parallel to a free surface. Application to a (111)Si low angle twist boundary. Philosophical Magazine, 2011, 91 (31), pp.1. ⟨10.1080/14786435.2011.600734⟩. ⟨hal-00723598⟩